Retear rates and clinical outcomes at 1 year after repair of full-thickness rotator cuff tears augmented with a bioinductive collagen implant: a prospective multicenter study

BACKGROUND: Biologic technologies can potentially augment existing arthroscopic rotator cuff repair to improve retear rates and postoperative outcomes. The purpose of this study was to evaluate healing rates and clinical outcomes of full-thickness rotator cuff repairs augmented with a bioinductive bovine collagen implant. METHODS: In this prospective multicenter study, investigators enrolled 115 patients (mean age, 60.4 years) with full-thickness rotator cuff tears. There were 66 (57.4%) medium (1-3 cm) tears and 49 (42.6%) large (3-5 cm) tears. Eligible patients consisted of those ≥21 years of age with chronic shoulder pain lasting longer than 3 months and unresponsive to conservative therapy. Patients underwent single- or double-row repair augmented with a bioinductive bovine collagen implant. At the baseline, 3 months, and 1 year, magnetic resonance imaging was performed and patients were assessed for American Shoulder and Elbow Surgeons (ASES) Shoulder Score and Constant-Murley Score (CMS). The primary failure end point was retear, classified as any new full-thickness defect observed on magnetic resonance imaging. RESULTS: There were 13 retears (11.3%) at 3 months, with an additional 6 (19 total [16.5%]) found at 1 year. In large tears, double-row repair had a significantly lower rate of retear at 3 months (P = .0004) and 1 year (P = .0001) compared with single-row repair. ASES and CMS scores significantly improved between the baseline and 1 year for medium and large tears. At 1 year, the minimally clinically important difference for ASES and CMS was met by 91.7% (95% CI: 84.9-96.1) and 86.4% (95% CI: 78.2-92.4) of patients, respectively. Patients without retear and those <65 years of age had significantly better CMS scores at 1 year when compared with those with retear and those ≥65 years (P < .05). There was no statistically significant difference in outcomes based on treatment of the biceps tendon. Of 9 reported reoperations in the operative shoulder, only 2 were considered potentially related to the collagen implant. CONCLUSION: Interim results from this prospective study indicate a favorable rate of retear relative to the literature and improvement in clinical function at 1 year after adjunctive treatment with the study implant augmenting standard arthroscopic repair techniques.